A stagecoach pulled by horses takes part in a show during the opening ceremony of the NEAT Gotthard Base Tunnel. [Photo/Agencies]

CONQUERING THE ALPS

The tunnel along Europe's main rail line connecting the ports of Rotterdam in the north to Genoa in the south snakes through the mountains as much as 2.3 km below the surface and through rock as hot as 46 degrees Celsius (114.8°F).

The old rail route crosses the pass in a series of loops and tunnels. The new flat route means even heavy trains will need only one locomotive rather than two or three.

Engineers had to dig and blast through 73 kinds of rock as hard as granite and as soft as sugar. Nine workers died.

"It is just part of the Swiss identity," Fueglistaler said of the Swiss fondness for major engineering feats. Swiss voters supported the project in several referendums in the 1990s.